This invention relates to foam dispensers and in particular to squeeze operated foam dispensers.
Liquid dispensers for dispensing soap and the like are well known. There are a wide variety of liquid dispensers for use in association with liquid soap. Some of these dispense the soap or other liquid in the form of a foam.
A common dispenser for liquid soap includes a cap with a nozzle portion that pivots from an in use position to a stowed position. In the in use position the nozzle is in flow communication with the interior of the dispenser. In the stowed position the distal end of the nozzle is inside the cap and thus liquid cannot escape. The advantage of this common dispenser cap is that it uses relatively few parts and is easy to use. The disadvantage is that when the dispenser is in the nozzle down position and the nozzle is in the in use position liquid will likely seep out continuously. A further disadvantage is that this can only be used in association with regular soap and it cannot be used to produce a foam.
Another dispenser for liquid soap is shown in U.S. Pat. No. 4,324,349 issued to Kaufman on Apr. 13, 1982. This dispenser includes a squeeze bottle, an air pocket structure disposed at the lower end of the bottle. The air pocket structure is in flow communication with the inside of the bottle and has an outlet so that liquid can flow from the bottle into the air pocket and out the outlet. The disadvantage of this squeeze bottle is that it can only be used in association with regular soap. It will not produce a foam.
Alternatively foam dispensers are used to dispense soap in the form of foam. The advantage of these dispensers is there tends to be much less waste due to splashing or run-off since the foam has a much higher surface tension than the corresponding liquid. In addition, foam tends to be much easier to spread than the corresponding liquid. Foam dispensers typically fall into two general types. One type produces foam by injecting a jet of air. The second type uses a porous material or mesh and a combination of liquid and air is mixed together and then forced through the mesh to form a foam.
One example of a foam dispenser is shown in U.S. Pat. No. 5,984,146 issued Nov. 16, 1999 to Kaufman. This foam dispenser includes a reservoir for containing a pool of liquid up to a predetermined level. The foam dispenser includes a discharge chamber which contains air above the level of the liquid and a discharge device which extends upwardly from the reservoir at least partly through the discharge chamber. The discharge device has an external outlet. The discharge device includes a foam chamber and pressure means, whereby pressure applied to the liquid in the reservoir drives liquid into the discharge device. This foam dispenser has a number of disadvantages. Specifically this foam dispenser includes a separate discharge or air chamber, which causes the device to be quite bulky. This foam dispenser has a number of components which make it more costly to manufacture than a device with fewer components. Further, the foam chamber of this foam dispenser has a plurality of very small pinprick sized holes in a tubular portion which would be difficult and expensive to produce. In addition, to modify this foam dispenser to produce different foam characteristics or to use a different consistency of foaming soap would require modifying the foam chamber and would be difficult and expensive to do.
Accordingly it would be advantageous to provide a foam dispenser that uses relatively few components, that is easy to produce and that is easy to use. Further it would be advantageous to provide a foam dispenser that is relatively compact.
The present invention provides a liquid dispenser for use in association with foaming liquid. The liquid dispenser includes a resiliently deformable bottle and a cap. The resiliently deformable bottle has an at rest position and an under pressure position. The bottle has an interior and a throat. The cap is attached to the throat and the cap has a nozzle extending inwardly into the interior of the bottle. The nozzle defines a nozzle fluid passageway. A nozzle cover is attached to the cap and spaced from the nozzle and a cap chamber is defined therebetween. An air tube defining an air passageway extends inwardly from the nozzle cover and the air passageway is in communication with the cap chamber and an interior portion of air formed between the liquid and the bottle in the interior thereof when the nozzle is positioned downwardly. A pressure actuated valve selectively opens and closes the air tube whereby the valve is closed when the bottle is in the at rest position and opens responsively to the bottle being moved from the at rest position to the under pressure position. A cover port is formed in the nozzle cover to provide a fluid passageway between the interior and the cap chamber. The dispenser includes a method of sealing the nozzle when the bottle is in the at rest position. The sealing method may be a pressure retaining valve. Alternatively the cover port, the nozzle and the nozzle cover are arranged whereby, in the at rest position with the throat of the bottle positioned downwardly, there is an airlock between the nozzle and nozzle cover in the cap chamber and when the bottle is moved from the at rest position to the pressure position the air lock is broken.
Further features of the invention will be described or will become apparent in the course of the following detailed description.